A golfer typically selects a golf ball that has a combination of features and performance characteristics based on his or her preferences and/or skill. The various performance characteristics may be provided by selection of materials and structural configurations, as well as manufacturing techniques. Different portions of the ball (for example the inner core and the outer surface layers) may be formed to have differing mechanical properties and other physical attributes. These differing properties and attributes determine the performance characteristics of the ball. For example, a ball having more weight toward the outer surface will maintain more spin during flight, which may be desired by the player. In addition, the hardness and/or compressibility of different portions of the ball influence the distance, control, and feel of the ball when played.
Golf balls have been developed that utilize relatively soft and/or compressible outer layer materials to improve spin and/or feel. However, soft and/or compressible materials may lack desired levels of durability for use in a surface layer of a golf ball, which experiences significant amounts of abuse from contact with golf club heads and from the ground. In addition, golf balls having soft and/or compressible outer layers may not provide desired levels of distance when struck.
In addition, the aerodynamics of the golf ball outer surface also influences the performance characteristics of the ball. Golf balls have been developed having dimples or grooves to provide desired aerodynamic effects. However, such balls have not taken advantage of the discontinuity in the outer surface of the ball by incorporating different materials in the dimples and/or grooves.
Some golf balls have been developed that include inner materials that penetrate the outer cover layer at some points, for example, to provide indicia on the outer surface of the ball. These golf balls are provided with a minimal difference between the hardness of the inner material and the outer cover layer material, for example, for example no greater than 15%, in order to provide consistency in the performance characteristics of the outer surface of the ball. Thus, such exposed inner materials are not implemented to provide an enhanced performance attribute, but rather, are merely for aesthetic benefit (as indicia). In other cases, hard material inlays, such as stripes, have been provided on golf balls, to provide different play characteristics depending on where on the outer surface the ball is struck. However, such differing play characteristics are prohibited by some rule-making golf organizations.
Some golf balls have been developed that utilize plugs that extend through the outer cover layer. The plugs may have a higher or lower hardness than the outer cover layer material. However, these plugs are flush with the outer surface of the outer cover layer. Accordingly, embodiments having softer plugs may be susceptible to wear of the plugs, since the softer materials may be less durable than the harder outer cover layer.
The present disclosure is directed to improvements in golf balls.